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authorRussell King <rmk+kernel@arm.linux.org.uk>2012-10-11 13:55:04 +0400
committerRussell King <rmk+kernel@arm.linux.org.uk>2012-10-11 13:55:04 +0400
commita0f0dd57f4a85310d9936f1770a0424b49fef876 (patch)
tree2f85b8b67dda13d19b02ca39e0fbef921cb1cf8b /Documentation/virtual/kvm/ppc-pv.txt
parent2a552d5e63d7fa602c9a9a0717008737f55625a6 (diff)
parent846a136881b8f73c1f74250bf6acfaa309cab1f2 (diff)
downloadlinux-a0f0dd57f4a85310d9936f1770a0424b49fef876.tar.xz
Merge branch 'fixes' into for-linus
Conflicts: arch/arm/kernel/smp.c
Diffstat (limited to 'Documentation/virtual/kvm/ppc-pv.txt')
-rw-r--r--Documentation/virtual/kvm/ppc-pv.txt22
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diff --git a/Documentation/virtual/kvm/ppc-pv.txt b/Documentation/virtual/kvm/ppc-pv.txt
index 4911cf95c67e..4cd076febb02 100644
--- a/Documentation/virtual/kvm/ppc-pv.txt
+++ b/Documentation/virtual/kvm/ppc-pv.txt
@@ -174,3 +174,25 @@ following:
That way we can inject an arbitrary amount of code as replacement for a single
instruction. This allows us to check for pending interrupts when setting EE=1
for example.
+
+Hypercall ABIs in KVM on PowerPC
+=================================
+1) KVM hypercalls (ePAPR)
+
+These are ePAPR compliant hypercall implementation (mentioned above). Even
+generic hypercalls are implemented here, like the ePAPR idle hcall. These are
+available on all targets.
+
+2) PAPR hypercalls
+
+PAPR hypercalls are needed to run server PowerPC PAPR guests (-M pseries in QEMU).
+These are the same hypercalls that pHyp, the POWER hypervisor implements. Some of
+them are handled in the kernel, some are handled in user space. This is only
+available on book3s_64.
+
+3) OSI hypercalls
+
+Mac-on-Linux is another user of KVM on PowerPC, which has its own hypercall (long
+before KVM). This is supported to maintain compatibility. All these hypercalls get
+forwarded to user space. This is only useful on book3s_32, but can be used with
+book3s_64 as well.